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Phosphorus Availability Regulates TORC1 Signaling via LST8 in Chlamydomonas.
- Source :
-
The Plant cell [Plant Cell] 2020 Jan; Vol. 32 (1), pp. 69-80. Date of Electronic Publication: 2019 Nov 11. - Publication Year :
- 2020
-
Abstract
- Target of rapamycin complex 1 (TORC1) is a central regulator of cell growth. It balances anabolic and catabolic processes in response to nutrients, growth factors, and energy availability. Nitrogen- and carbon-containing metabolites have been shown to activate TORC1 in yeast, animals, and plants. Here, we show that phosphorus (P) regulates TORC1 signaling in the model green alga Chlamydomonas ( Chlamydomonas reinhardtii ) via LST8, a conserved TORC1 subunit that interacts with the kinase domain of TOR. P starvation results in a sharp decrease in LST8 abundance and downregulation of TORC1 activity. A hypomorphic lst8 mutation resulted in decreased LST8 abundance, and it both reduced TORC1 signaling and altered the cellular response to P starvation. Additionally, we found that LST8 levels and TORC1 activity were not properly regulated in a mutant defective in the transcription factor PSR1, which is the major mediator of P deprivation responses in Chlamydomonas. Unlike wild-type cells, the psr1 mutant failed to downregulate LST8 abundance and TORC1 activity when under P limitation. These results identify PSR1 as an upstream regulator of TORC1 and demonstrate that TORC1 is a key component in P signaling in Chlamydomonas.<br /> (© 2020 American Society of Plant Biologists. All rights reserved.)
- Subjects :
- Chlamydomonas genetics
Chlamydomonas reinhardtii genetics
Chlamydomonas reinhardtii metabolism
Gene Expression Regulation, Plant
Intracellular Signaling Peptides and Proteins genetics
Mechanistic Target of Rapamycin Complex 1 genetics
Nitrogen metabolism
Plant Proteins metabolism
Signal Transduction genetics
Transcriptome
Triglycerides metabolism
Chlamydomonas metabolism
Intracellular Signaling Peptides and Proteins metabolism
Mechanistic Target of Rapamycin Complex 1 metabolism
Phosphorus metabolism
Signal Transduction physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1532-298X
- Volume :
- 32
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 31712405
- Full Text :
- https://doi.org/10.1105/tpc.19.00179